


A story in which Ruby gets a harem

by HeyHeyItsFei



Category: Love Live! Sunshine!!
Genre: Breeding, Cum Inflation, Dick Growth, F/F, Futanari, Huge Butt, Lactation, Large Breasts, Large Cock, Masturbation, Nipple Play, Vaginal Sex
Language: English
Status: Completed
Published: 2020-09-27
Updated: 2020-10-16
Packaged: 2021-03-07 19:20:36
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 3
Words: 11,574
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26672815
Author URL: https://archiveofourown.org/users/HeyHeyItsFei/pseuds/HeyHeyItsFei
Summary: After being subjected to Mari's cooking, Ruby and the rest of aqours undergo some changes that lead to some unprecedented situations.
Comments: 2
Kudos: 38





	1. Chapter 1

**Author's Note:**

> First chapter is just building up to what's to come. Smut will be every chapter onwards.

It was just supposed to be a regular Saturday night to celebrate Mari coming back from an overseas trip; the blonde had invited all of Aqours to her hotel flat with the intention of spending the evening partying, eating food and watching a movie. All of the girls were quick to accept without an ounce of hesitation, thinking that they’d be treated to the upper class meals that Mari frequently indulged herself in.

They weren’t prepared to see the host herself preparing dinner. Previously, Mari’s cooking had proven to be more otherworldly than anyone could imagine, hindering on the border of inedible and toxicity. The bossy Dia had popped off and scolded the blonde cook for trying to subject them to her concoction, insisting that they’d all fall ill if they did attempt to eat whatever they were presented with.

Mari shrugged it off, standing firm and assuring the older Kurosawa sibling that she’d learned how to make a special dish while she was overseas, and that she had brought back some ingredients so she could share with her friends. “Dia, you can glare at me with those nasty eyes all you want, I promise that this will come out perfectly fine. If you are a good girl, maybe I’ll spoon feed you,” as she flashed her charming smile, Mari was aware that she was hitting all of Dia’s buttons.

Scoffing and stomping back to join the others lounging around in the living room, Dia still couldn’t bring herself to trust Mari’s cooking, not after the stewshine incident. Seating herself next to Kanan who had a sympathetic look on her face, the black haired girl tried to relax her nerves so as to not spoil the mood. She didn’t want everyone to feel awkward, especially with how happy her beloved younger sister seemed to be.

Ruby was seated on the ground, gossipping with Chika, Yoshiko and Hanamaru about their plans for the following day, and how there was a new sweet store opening up in the shopping mall that the twintailed girl was passionate about visiting. With a pure smile on her face, Ruby was blissfully unaware of what Mari’s cooking would bring upon the whole group of girls. She knew that the older girl wasn’t the best chef, but she wanted to believe that Mari’s skills had improved, especially with how confident she seemed to be.

It was only moments later that Mari had called for everyone’s attention that dinner was prepared. Mixed reactions of hesitation sprung from the group, Kanan stepping forward to try and act like a role model towards her peers, wanting to at least show them that they should be polite towards the blonde and show some appreciation for the amount of effort she put in. Expecting to have to dish up her own plate, the cool headed girl was surprised to find that Mari had prepared it all herself.

As each girl found themselves taking their servings of food, they were all shocked to find that Mari had actually prepared a decent looking dish. Roasted pork belly with roasted carrots, broccoli, and eggplant, with a pinch of garlic sprinkled on top. If you were to compare this dish with her previous stewshine, you would never guess that they were prepared by the same cook. What the blonde failed to mention is that she used red wine in the stock pot, blissfully unaware that she was serving this dish to minors who probably had no experience with such rich flavours. As Mari sat down between Kanan and Dia on the couch, she was happy that everyone seemed to be pleased with what she had cooked. Leaning back to watch the cartoon about a talking sponge that Ruby had put on, she Mari was content with how things had turned out. That is until everyone had taken a bite of their meal.

As Ruby took a piece of pork and placed it in her mouth, you could count on one hand the amount of seconds it took for her face to turn red. Almost as if it was a repeat of Yoshiko’s takoyaki, the twintailed girl found her mouth burning from the sudden assault of spices. Quick to her feet, Ruby started screaming as she ran around the flat, almost as if she was breathing fire. Finding herself in the kitchen, she was quick to turn on the tap and just throw herself into it, drinking in the flowing water as if her life depended on it.

All eyes were on Ruby during this, everyone either concerned or amused with the act unfolding before them. Dia was unimpressed as her dearest sister was suffering from attempting to eat Mari’s cooking. Having found the dish to be delicious from the two bites she had taken, Dia was about to raise her voice and go off at Mari before the girl in question decided to speak first. “S-Sorry, I may of uh.. Used some spices. Please don’t kill me, I have so much to live for!” Clinging herself to Dia’s chest in a hug, begging for mercy as the thought of Ruby’s intolerance for spicy food had slipped her mind completely.

As Ruby seemed to calm herself down, Dia couldn’t bring herself to hold it against Mari for not warning anyone about what she had prepared. Curious as to what Mari had used, Dia decided to question the blonde. “So what did you use, Mari? You just come back from overseas and all of a sudden you prepare such a treat for us. What gives?” Sitting herself up straight, Mari took a moment to think of what she had exactly used. Clapping her hands as the gears in her head decided to spin, the blonde spoke, “Well I just brought back the vegetables and spices, everything else I picked up at the store. Why, what’s wrong?”

Her worries being quelled for now, Dia took a moment to check on Ruby’s wellbeing before returning to finish dinner. As each girl cleared their plates, Ruby struggling to finish it without breathing fire like a dragon, they were all starting to find their heads spinning simultaneously, their surroundings starting to become nothing more than a blur as they all lost consciousness.

An hour passed before any of the girls would awaken from their sudden slumber, each of them coming to shortly after one another, still feeling disoriented and trying to understand what exactly had happened to them. Ruby was the last to come to as she rubbed her eyes, finding herself to be the first to be aware of her surroundings. Noticing that each of them was still half awake, the twintailed girl struggled to find the strength in her legs to stand up, eventually making her way to each of the others and giving them a shake to see if they were in the realm of the living or not.

As they all tried to come to terms with the sudden dizzy spell that hit all of them, none of them were able to make sense of what occurred. Deciding it for the best that they all call it a night and head their separate ways, worried that they were fatigued, all of the girls bid each other farewell and made their ways home. As they tucked themselves into bed that night, none of them had any idea on what changes were awaiting them when they were to awaken.

* * *

Ruby awoke the next morning with her blankets being lifted two feet into the air above her by a foreign object. Feeling like she was still dreaming, she rubbed her eyes as she threw the blankets off of her, not prepared for what she was about to find.

Standing erect and tall was a throbbing, huge manhood that was pointing upwards to the ceiling, accompanied by two heavy, grapefruit sized balls resting beneath it. In disbelief at what she was seeing, Ruby reached out to touch the foreign penis, rubbing her small hands along it in awe. She wasn’t sure just how big it was, but all she knew was that it wasn’t there the day beforehand.

Wondering where it had sprung up from, Ruby found her grip on the phallus tightening up as she continued to rub her hands up and down the length. Letting out a moan of pleasure, she was unsure with what exactly she was feeling or seeing. Picking up the pace as vocalised pleasure left her mouth, Ruby found herself wanting more. Minutes had passed as she continued to furiously stroke her manhood, beads of sweat running down her forehead as the bed started to shake from the sheer intensity of her masturbation.

Not caring whether she alerted her family with the amount of noises coming from her, Ruby was focused on reaching the building pleasure as she started to throw her head backwards and throw her hips upwards, panting and letting her tongue slip out of her mouth as saliva started to drip down off of it. Feeling the pent up pleasure ready to burst, Ruby was about to climax when a knock on her door brought her back to reality.

“Ruby, are you awake? I want to go shopping soon and thought I’d ask if you wanted to come with me.” Dia’s voice spoke calmly through the door, unaware of the deeds that her pure, beloved younger sister was committing in privacy. Taking a moment to regain her thoughts, Ruby was brought back to her senses.  _ What was I even doing?  _ Questioning her actions, she was quick to brush that thought away, worried that Dia would walk in on her.

“U-Um, give me a while, onee-chan,” breathing heavily, the young girl was trying to remain as composed as she could. So many questions were running through her head.  _ Where did this thing come from? Why do I have it? Why do I want to pleasure myself?  _ Overcome with a rush of emotions, Ruby didn’t know what to make of what was happening to her.


	2. Chapter 2

**Summary for the Chapter:**

> Ruby wants answers and goes to Mari in hopes that the blonde can enlighten her.

**Notes for the Chapter:**

> let ruby say fuck

Slowly and taking her time to leave bed, still unsure what to make of the sudden cock that sprouted from her crotch overnight, Ruby waited outside the bathroom she shared with Dia, discomfort written all over her face as she shifted on the spot. Knocking on the door to check if anyone was inside, the young girl was taken back when a black haired beauty opened the door, wrapped in a towel with water dripping down her body.

The towel left nothing to the imagination as it clung tightly to Dia’s body, her breasts threatening to overflow at any second as she was shocked to see Ruby standing there with empty eyes at the door. Normally the doting older sister would pry and insist on knowing what was wrong with her dearest younger sister, but Dia could only stare speechless as she felt her heart rate increasing as the silent seconds passed by.

Finding her sister in the bathroom after having come out of the bath was nothing surprising to Ruby, but she felt that something was off. Looking up and down at Dia’s body, she couldn’t quite put her finger on exactly what was wrong with the image in front of her. As she inspected her sister’s frame, Ruby couldn’t help but marvel at how mature and womanly Dia’s body was.

Large breasts that the refined girl kept hidden away, a round rear that made you want to smack it, and her long, slim legs that were topped up with juicy, succulent thighs that you couldn’t help but want to call thick. As Ruby’s eyes focused on Dia’s chest, it finally clicked with her just what was wrong with the picture in front of her. Letting out a gasp and stepping back in surprise, the young girl was unable to mask her astonishment.

_ God, my sister’s chest is massive.  _ Unable to pry her eyes away from the large rack, Ruby was certain that Dia wasn’t  _ this  _ big yesterday morning, having also ran into her sister at the bathroom. As her rational thoughts started to be brushed aside, Ruby’s mind was starting to become clouded with thoughts of her sister and how attractive she was.

Normally, Dia would’ve been quick to realise when someone was eyeing off her body as she had experience with a certain blonde girl who liked to let her hands roam and feel up girls she liked, but as she looked down at Ruby, she felt conflicting emotions rising to the surface. She cherished her cute little sister and wanted to protect her, but Dia was starting to develop feelings for the girl. She wanted to grab a hold of her sister right this second, pin her against the wall and commit a taboo act.

With a loud, echoing slap to her cheek, Dia brought herself back to reality as she thought to herself,  _ I can’t think of Ruby that way. She’s my sister for crying out loud. What is wrong with me?  _ The stinging pain a reminder of her sinful thoughts, the towel clad girl could feel her thighs starting to grow damper with each passing second. Thinking that it was just the bath water, Dia made nothing of it before speaking up.

“U-Um.. I’ll go get dressed and prepare breakfast,” rushing to get the words out, Dia left no room for a response before she took off towards her own room, her face turning red as her heart threatened to burst out of her chest. Confused as to her sister’s behaviour, Ruby’s eyes followed Dia until she disappeared from sight, feeling guilty for having such disgusting thoughts cross her mind. She had never considered anyone attractive before, so why was it her sister of all people to spark this?

Stepping into the bathroom and closing the door behind her, Ruby was quick to shed her clothes, freeing her erect cock from its restraints. She wasn’t aware of when it had grown hard, but as she continued to recall the events that had just transpired, her member would throb as if it was demanding attention. Unsure on what was wrong with her, Ruby could only blame the sudden protruding phallus for such indecent thoughts that were swirling around her head.  _ Yeah, it’s all your fault.  _

Grabbing hold of it with both hands with a tight grip, almost as if she intended to strangle it, Ruby started to pump her hands up and down the large length, her face not hiding her irritation. As she continued to stand there, pleasuring her throbbing manhood there in the bathroom, Ruby’s legs were starting to turn to jelly as moans of pleasure started to erupt from her lips. There was one person on her mind, and Ruby wanted nothing more than to take out her frustration on her.

The pleasure was starting to build up inside of her as beads of sweat started to run down her head, the young girl holding nothing back as her hands ran from the base to the head, repeating the process over and over. Ruby could feel that something foreign was coming, wanting to be released. As if she was possessed by a beast in heat, she could only focus on releasing all of this pent up frustration.

Slowly making her way over to the toilet, her legs were almost jelly like, Ruby rested one of her hands against the wall to hold her body up as she could feel strength escaping her while she continued to pump her huge cock with the other hand. Letting out a loud moan and panting heavily, Ruby could feel that something was screaming to be released and it was coming like a storm. Feeling like she was about to burst, she threw her head back and screamed.

“O-Onee-chan!!”

As if vocalising the name was enough to set her off, a torrent of thick, white cum started to erupt out of the tip of her manhood, blast after blast landing into the toilet beneath her. Her body shaking from the sheer intensity of her first ejaculation as she couldn’t feel an end in sight as her mind was clouded with nothing but the thought of her beloved sister. Almost like the mere thought of Dia was enough to urge her on more, Ruby could feel shot after shot continuing to erupt from the red monster that had sprouted from her crotch.

After a moment, her orgasm subsided as she could feel her legs giving out as she fell backwards onto the floor landing on her rear. Ruby could feel her mind clearing up, the clouds lifting as her cock started to wither, cum dripping from the head onto the ground beneath her as the adulterous smell filled the room. Taking a second to gather herself, the post-nut clarity started to hit her.

_ What have I done?  _ Overcome with guilt, Ruby couldn’t believe herself; she had just gotten off to the thought of her older sister of all people. She had never pleasured herself before and was blissfully unaware of anything related to such adulterous acts, Ruby was overwhelmed with what she had just done. Breathing heavily as if she was starved for air, she felt like her heart was about to burst out of her chest.

Slowly picking herself up off the ground, the young girl looked on in awe at what she had just let out of her body. Not wanting to look at the evidence of her sinful deeds any longer, she flushed the toilet and let her ejaculation wash away, hoping to herself that her memories of what had just happened could also be discarded like that. Not wanting to waste any more time, Ruby was quick to jump in the bath and continue her day.

* * *

  
Having to act like nothing was wrong while she left to go shopping with Dia, Ruby was full of discomfort as she put on a fake smile. She couldn’t begin to imagine what would happen if anyone were to discover what she had just done, and she didn’t want to. She feared being thrown out and disowned for such taboo acts. This didn’t stop her from admiring her older sister though.

Dia was clad in a white, short sleeved shirt that put her right shoulder on display, with a short back shirt to compliment it. Something simple that worked with the refined girl. Normally Ruby wouldn’t think much of what her sister was wearing, but with what had happened earlier in the morning, she couldn’t bring herself to not notice it. Of course, Dia’s clothes were a perfect fit for her prior to her sudden growth spurt overnight.

But now the clothes clung tightly to her body, clearly a size or two too small for the black haired beauty. Her large chest brought the shirt up, putting her navel region on display for the world to see while her butt had also grown, her knee length skirt now rising up to the middle of her thighs. If she were in a clear state of mind, Dia would’ve refused to wear such clothes that put herself on display, but upon waking up that morning, she felt like there was something different about her and she couldn’t quite put her finger on it.

Ruby also couldn’t quite confirm or deny it, but she felt like her sister wasn’t wearing a bra either as she watched Dia’s breasts bounce with each step. She wanted to think that it was just her own degeneracy rising to the surface yet again, but she also felt that something was off about Dia. The normally mature and polite girl’s face was red the entire time since they left the house, as if she was drunk.

“Ruby, I want to go buy some clothes. Do you want to join me?” The question brought Ruby out of her daze. Dia was looking at the shorter girl with a gentle, caring look that she often showed when referring to her beloved sister. As she stared at Ruby, she could feel a shiver flow through her entire body as her nipples started to become erect as her panties began to grow damp. She was unaware as to why she felt this way when she was alone and thinking of her sister of all people, but Dia brushed it off and assumed that it was just the aftermath of last night.

“I-It’s okay, onee-chan. I have some stuff I want to do,” flashing her sister a smile with a shaky voice, Ruby knew that the longer she spent with her sister, the more insane she would grow. She also had an idea in mind that she wanted answers for, and having Dia around would hinder it. With a disappointing tone, the older sister looked down as if upset, “I-I see. Well that’s fine. I’ll catch you later, okay? Stay safe and keep your phone on.”

Dia wanted to spend time with her dearest Ruby, but she didn’t want to come off too forcefully. As she waved and walked away, heading towards some clothing stores, she let out a sigh of relief as her heart rate started to calm down as she felt a weight off of her shoulders. Like a wave of fresh air had hit her, Dia was clear headed now that she had gotten away from Ruby, and she was oblivious as to why her head was spinning so much when they were together.

Ruby could only watch as her older sister disappeared from sight, having headed towards the clothing stores to obviously find something that fits her developed body. She wanted to call out that Dia was walking into a gal fashion store, clearly thinking that it must be a mistake as the strict girl was adamant about her distaste of such a style. The super short skirts and shorts that put so much skin on display, the shirts that hugged the curves and showed off the belly button, and the makeup that was so flashy.

Not wanting to make a scene as her sister was already gone, Ruby confirmed her resolve before making her way back to where the events had transpired last night; Mari’s residence. She knew that she wasn’t going to get any answers otherwise, but trying to get some information from the blonde was the first step in understanding just why she had grown her own set of male genitalia and why her older sister was acting so strangely.

Not giving Mari any notice in advance of her arrival, Ruby was determined to get to the bottom of this strange development of things. Knocking on the door to Mari’s flat, she waited patiently, fully expecting the rich girl to not be around. After a minute of waiting, the twintailed girl was ready to leave when the door opened up to reveal the blonde girl clad in nothing but a bathrobe.

“O-Oh it’s you, Ruby. What’re you doing here? Did you finally decide to become my little sister?” Her expression going from surprised to jokingly smiling, Mari didn’t hold back her usual teasing. She wasn’t expecting anyone to visit her and of all people to be the younger Kurosawa sibling. As she ushered Ruby inside, she could feel her heart begin to race as she pushed back the thought that she was naked beneath the bathrobe.

“N-No.. I’m only onee-chan’s sister. But um..” Taking a seat on the couch, feeling some comfort from the usual joking atmosphere coming from Mari, Ruby took a sigh of relief to see that the older girl was behaving as normal before continuing, “W-Well you see, onee-chan’s been acting weird since last night and um.. I just wanted to know if you knew anything, Mari-senpai.” Surprised that when she mentioned her sister that her heart didn’t begin to race or that her thoughts didn’t start to become perverted, Ruby couldn’t get rid of the nagging feeling inside of her.

“Oh Dia’s giving you the cold shoulder and now you come running to me in hopes that I’ll make you my little sister? I see, I see.” Mari was playing around as usual, but she was thinking to herself about why the strict girl in question would be acting strangely. With nothing coming to mind, she shook her head as if to say that she would have no idea. Sinking back in defeat, Ruby felt like she had wasted her time coming here.

Her eyes landed on the blonde girl that was seated next to her on the couch, taking in every nook and cranny that she could see. Ruby knew that Mari had the largest bust size in all of Aqours, but couldn’t help but think that it had also grown in size like her sister’s had. Dressed only in a bathrobe, Mari’s body was on almost on full display to the younger girl as her eyes continued to survey her frame.

Her heart rate increased as she felt her mind becoming overcome with thoughts of the cheerful girl, thinking to herself that Mari was sexy. Shaking her head to erase such lines of thinking, Ruby could feel the blood starting to flow into her manhood as it began to grow in size. She knew that sexualising her senior like this was wrong, and getting aroused at the mere thought and sight of her was something to be ashamed of, but she couldn’t control herself.

Mari herself could feel her own heart racing as Ruby continued to stare at her with such a longing gaze, feeling herself thinking of nothing but the delicate young girl next to her. The gears in her head started to turn before the lightbulb lighted up before she clapped her hands together before opening her mouth, “Oh I know! So like, you know how I brought back ingredients from overseas? Well uh.. I kind of bought them from some shady looking store and uh.. Didn’t think much of it.”

Her daze broken and surprised that Mari had brought her back to reality with some actual information, Ruby took a second to process things. “S-So you’re saying that whatever happened to onee-chan is because of whatever you made last night? Am I getting this right?” Not wanting to believe such a fantasy-like string of events, she was aware that this was the only plausible outcome at the current time.

“W-Well I guess? I don’t know, nothing has happened to anyone else right? Like, I’m fine and you’re fine. No?” Mari was trying to be sensible about this, although a part of her wanted to play around and let things play out.  _ There’s no way that my cooking could actually do anything, right?  _ Telling herself that, the blonde girl was forgetting one piece of information; what exactly had changed about Dia.

_ Am I the only person aware of what kinds of growths have occurred since last night?  _ Ruby was monologuing to herself, feeling like she was the odd one out as both Dia and Mari were oblivious to the changes that their bodies had experienced. “Mari-senpai, you’ve changed as well you know. Why are you in nothing but a bathrobe that barely fits? Better yet, did you not notice that your um.. Chest has grown?” Feeling somewhat embarrassed at calling attention to the blonde girl’s body, Ruby’s rational train of thinking was set to depart as a tsunami of indecent thoughts rushed in. Ogling at Mari’s gigantic chest, the young girl wanted to pin the blonde girl down and have a taste of her.

Mari was ignorant of what Ruby meant as she groped her own chest and gave both her breasts a good squeeze before speaking up, “There’s nothing different about them, Ruby. Here, see for yourself.” Opening up her robe to put her breasts on display, her large areola and inverted nipples being the first thing that caught Ruby’s attention. Mari herself could feel her a tingling between her thighs as they grew damp, not embarrassed with putting her nude body out in the open like that.

Having worn a skirt that hangs down just above her ankles, Ruby’s erect cock was raising it upwards as if it had a mind of its own, screaming for release from the fabric constraining it. She was turned on by Mari, and her putting herself on display like that only added fuel to the fire. Her mind clouded by lust, Ruby spoke sensually, “Mari-senpai, you’re pretty stacked. Maybe we should refer to you as a cow since they look like they’ll produce tons of milk.”

Being spoken down to like that would normally set anyone off, but with Mari’s mind spinning with thoughts of Ruby, she couldn’t even offer a retort, only capable of agreeing with the remark, “Y-Yeah I’m a cow, Ruby. They’re so big and heavy that I could probably use it for cereal.” Nodding her head, the blonde’s eyes were clouded as she stared at the tent pitching in the young girl’s skirt.

As if she was possessed, Ruby reached forwards and took a firm hold of Mari’s breasts, her fingers sinking into the soft flesh as her eyes never left the gigantic mounds. “If you’re a cow, then I need to milk you, yeah?” With a serious tone, the twintailed girl didn’t wait for a response before she started tugging, pulling and squishing Mari’s chest, playing with it as if she were a child.

Letting out a moan in surprise, Mari was welcoming of the aggressive attention being given to her breasts. She wanted to be treated like a toy, being played with roughly and without care for her own feelings. Buried in the back of her mind, a part of her was screaming that what was happening was inappropriate and that she should put an end to things, but it was silenced by the spiral of lust that was clouding her thoughts.

“M-More.. Dig your fingers in and pull my nipples out by force, Ruby,” giving herself in, Mari could only relay her desires to the younger girl in hopes that she’ll give her the satisfaction and pleasure she craved for. Growing irritated with being told what to do, Ruby dug her fingers into Mari’s breasts to try and pull the inverted buds out. With moan after moan escaping from the blonde’s lips, this was all the encouragement the twintailed girl needed.

“Mari-senpai.. No, you’re nothing but a cow now. Did I give you permission to speak? Please tell me, when did I ask for you to tell me what to do?” Glaring at Mari as she spoke all of this, Ruby was irritated with an animal that’s only purpose was to produce milk, having the gall to tell its owner what to do.  _ Yeah, you’re my pet.  _ A devilish grin came across her face as she continued to toy with the large sacks of flesh, Mari’s nipples finally surfacing from hiding.

“A-Ah.. M-More.. Harder..” Mari couldn’t respond, she could only ask for more attention from her attacker. Feeling her womanhood growing wetter with each passing second, she knew that it was going to be like a waterfall if things continued like this. But she didn’t want things to come to an end. No, Mari wanted to give herself up to Ruby and let the young girl breed her like the animal she was.

Tugging on Mari’s nipples with reckless abandonment, Ruby had one thing in mind; she wanted to release this pent up frustration and she was going to use Mari’s body to achieve it. Pulling one nipple towards her while squishing the other breast, Ruby was amused with the music emitting from the blonde’s mouth as moans filled the air. With one final pull on each bud, a liquid started to flow from Mari’s breasts.

“Oh so the cow is finally deciding to produce milk? And here I thought you were a useless animal that was good for nothing.” Intrigued with the sudden production of breast milk, Ruby could only condescendingly speak to her senior as she continued her rough assault. If either of the girls were in a rational mindset, they would know that this shouldn’t be happening; Mari definitely wasn’t pregnant so she shouldn’t be able to lactate. But the pair were lost in the insanity, drowning in an ocean of lust.

Letting out a loud, drawn out moan, Mari could only throw her head back and rub her thighs together before finally gathering enough sense to desperately speak, “A-Ah.. Yes, I’m a worthless cow. I’m  _ your  _ pet who is only good for producing milk and breeding, so please, PLEASE make the most out of my body and make me squirm from your touch.” She was long gone, any rational thoughts that could possibly put an end to things were washed away as Mari was ready to give herself up to Ruby.

“That’s a good slut,” the dominant girl spoke smugly as she closed the distance between the two, planting her lips on Mari’s lips and stealing a kiss, not an ounce of gentleness to be shown as she took control of the blonde girl’s mouth, invading it with her own tongue and proving dominance as they shared saliva with one another. Mari could only moan back in approval, loving being treated like she was worthless.

After a hot, intense moment of kissing between the pair, Ruby pulled herself back as a string of saliva connected the girl’s tongues together. Reaching up with a finger, she took the line of clear liquid and wiped it across Mari’s red face, the girl breathing heavily as she offered no protest to the disrespect she was being shown. Ruby stood up from the couch and began to undress, freeing her raging monster from its constraint.

Mari could only gaze in awe at the sheer size of the member sprouting from Ruby’s pelvis, feeling herself growing damper as the thought of what the young girl was about to do with such a menacing thing flowed through her mind.  _ Fuck I need a piece of that.  _ Licking her lips, Mari lifted herself up briefly to toss her bathrobe aside before sitting back down and spreading her legs wide open, her drenched pussy on display for the young girl.

“Cow’s are meant to be bred, no? It’d be pretty stupid for me to neglect such a thing, and as your master I have to take responsibility for you.” Looking down at the lactating blonde, Ruby’s throbbing manhood was dripping with precum as she knew what she had to do; she had to let her animalistic instincts take control and fuck Mari senseless until she was pregnant. And with how far lost the pair of them were in the craziness, she knew that there was nothing to stop her.

“Now be a good girl and accept your master’s love. Understood?” Approaching Mari, Ruby’s grapefruit sized balls bounced with each step as she stared down at the girl. Mari could only nod her head, still awestruck with the monstrous member protruding from Ruby’s slim frame. If she was in a rational state of mind, Mari would scream that such a large member would never fit inside, but having been swallowed by lust, she didn’t care whether it was impossible or not, she just wanted that enormous dick to reshape her aching pussy.

Pressing her engorged cock head against the soaking wet folds of Mari’s womanhood, Ruby grabbed hold of both of the outstretched legs, holding them firmly in place as she started to move her hips forwards. From an onlookers perspective, you would see that an object that was impossibly too big to fit was trying to force its way inside of a hole that was way too small. Neither of the girls cared though as the head of Ruby’s dick pushed its way into Mari’s pussy, spreading it wide open.

With Mari letting out a gasp of surprise followed by a scream of pain as her womanhood was spread unimaginably wide, Ruby took it upon herself to thrust her hips forwards with reckless abandonment, intent on getting all of her aching penis to the brim inside of Mari’s tight, no longer virgin pussy. An ear piercing scream erupted from the blonde’s lips, her hymen being torn and feeling like she was being torn in two as milk started to spray from her large breasts.

Only having half of her monstrous dong plunged inside of Mari, Ruby was discontent with herself; she wanted to drive all of her manhood inside of the drenched pussy and reshape it to her fit, but she was met with some resistance. Having driven her cock head against Mari’s cervix and reaching a wall that just wouldn’t budge, Ruby pulled her hips backwards till only the tip remained inside before plunging back down furiously.

“Y-You.. You worthless cow! S-Such a tight pussy that isn’t capable of satisfying your master. A-Ah.. How dare you.. How dare you have the nerve to call yourself MY pet!?” Pivoting her hips and letting the pleasure take control, Ruby was displeased with the chain of events. Like an animal in heat, she fervorously thrusted in and out of Mari’s twitching pussy, wanting to bury herself to the hilt and blowing the biggest nut possible directly into her fertile womb.

Mari could only moan and squeal in response, the pain of being torn open replaced with pleasure as she could do nothing but throw her head back, milk still spraying from her gigantic breasts. She was incapable of forming words, helpless as Ruby had complete control. She wanted to give the dominant girl everything she could, and she was intent on having that itch be sated. It wasn’t long before the building pleasure had reached it breaking point and the blonde girl was hit with an orgasm, her walls squeezing around the monstrous cock hammering away at her pussy as she screamed, “R-RUBY!!”

Her body started to convulse from the intensity of the climax, the foreign experience frying her mind as she was incapable of forming words, only able to let out animalistic noises and moans from her mouth. Mari could only think of one thing; getting bred by Ruby. Feeling the blonde tighten up and emit some music, Ruby started to pick up her pace as she was intent on forcing all of her length inside of Mari’s trembling pussy, whether it was realistic or not.

One. Two. Three. Four. With each passing thrust, Ruby could feel the wall of resistance slowly giving way before finally, with one final pivot of her hips, she plunged her cock through Mari’s cervix and into the girl’s womb. Having reached a forbidden place, Ruby let out a moan of relief and pleasure as she buried herself to the brim inside the blonde girl, who was screaming her lungs out with her eyes rolled back into her head, the fountain of milk spraying from her breasts growing more intense.

Looking down proudly, Ruby noticed that Mari’s stomach was bulging outwards, the shape of the girl’s womb being stuffed full with her own cock bringing a smile to her face. Pulling herself out till only the tip remained yet again, Ruby spoke as she gasped for breath, “A-Ah.. You’re good. Y-You took all of your master’s dick. You’re my.. My..” Grabbing hold of Mari’s hips as she took one last breath before yelling, “YOU’RE MY SLUT!!”

With those words leaving her lips, she buried her cock to the hilt inside of Mari, causing the girl’s eyes to go wide as she let out a long moan. Mari could barely process what had been spoken, but she understood that she belonged to Ruby; she was a slave to her cock. Feeling the pleasure building up again, she knew that she was about to be hit with another intense orgasm.

Ruby herself was reaching her limit, doing her best to stop herself from dumping the contents of her balls that were repeatedly slapping against Mari’s body as she wanted to savour the moment. She knew that she couldn’t last much longer, but she wanted to absolutely wreck the blonde girl’s pussy beyond repair as she thrusted her hips fervorously. Groaning with each forward movement, Ruby was about ready to blow her load when Mari let out another deafening scream.

Mari’s own orgasm was enough to set Ruby off as the twintailed girl buried all of her monstrous manhood inside of the blonde’s tightening pussy, as she let out a howl-like moan as she felt her balls tighten up as something passed up and through her dick. “Aaaah.. T-Take it.. TAKE IT ALL!!” Exasperated, Ruby continued to thrust as a torrent of cum burst from her cock head and sprayed directly into Mari’s fertile, awaiting womb.

The intensity and heat from Ruby’s load was enough to set Mari off the deep end, as she let out one last moan before passing out, her womb being filled with shot after shot of potent baby batter. The volume of the dickgirl’s ejaculation was beyond that which she had let out earlier in the morning, quickly filling Mari’s pussy to max capacity within seconds. As spurt after spurt continued to flow out, Ruby knew that this was going to be a long, drawn out orgasm as she shuddered with each passing thrust.

Not paying attention to how deformed Mari’s body was becoming, Ruby let her orgasm run its course before it finally came to an end, her legs growing weak from the intensity of the load. Pulling herself out of Mari’s stretched out pussy, a waterfall of cum flowed out from the gaping orifice, pouring down onto the couch below her. Taking a moment to collect herself, Ruby marveled at the sight before her.

The blonde was unconscious, a fountain of milk still erupting from her large breasts, flowing down her breasts and onto her stomach. Her stomach however, was filled beyond imagination with cum that left the girl looking heavily bloated. Inflated with Ruby’s baby batter, Mari’s stomach was large enough that you could only compare it to a beach ball. Every now and then her body would twitch as cum continued to flow out of her gaping wide pussy, her inflated frame not growing any smaller from it.

_ Fuck did I really do that?  _ Ruby was amazed with the condition of Mari, unable to believe that she had been the one to do that. Her manhood still stood erect and covered in cum, as if she had never ejaculated and was raring for more. She had the carnal desire to fuck Mari again, intent on breeding the blonde girl. Weakly making her way forwards and grabbing hold of the unconscious girl’s legs, Ruby was ready to go for round two.

Her attention was brought to a ringing noise coming from her phone. Frustrated and yelling to herself, she reached down and picked the device up, “Of course I get interrupted when I’m about to fuck this slut to heaven and back..” As she read the caller ID, she fell silent.

It was Dia.

“Fuck.”

**Notes for the Chapter:**

> So yuh. Dia ain't the first one to receive some tender loving care from Ruby.  
> Surprise surprise.


	3. Chapter 3

**Summary for the Chapter:**

> The Kurosawa sisters spend a night of intense passion together.

Hesitant to answer the ringing device, Ruby knew that the longer she put this off, the more Dia would insist on calling and messaging her worryingly. Standing there naked, she was weighing her options; ignore the call and fuck Mari’s brains out again, resulting in her sister probably having a heart attack from worrying so much, or she could answer it and end things with the blonde here and now. Ruby’s mind was telling her to do the right thing and reassure Dia that everything was fine, but her body was telling her to just ignore it, her erect dick still towering over the unconscious Mari’s body.

In the end, the nagging feeling in the back of her mind won and she reached down to pick up her phone. Taking a deep breath to try and calm her nerves down, and in an attempt to get the frustration she was feeling out of her body, Ruby picked up the phone. Before the young girl could speak, she was blasted by the voice on the other end of the line. “Ruby, thank god you’re safe. I thought something had happened to you. Haven’t I told you that you should always keep your phone on you and be ready to answer my calls?” The lecturing yet concerned tone of Dia’s was loudly coming through, the girl worried sick that her darling younger sister could have possibly been kidnapped or hurt.

“Onee-chan, I’m fine really. I was just.. I was in the middle of something and couldn’t answer right away. Sorry for worrying you,” feeling guilty for causing grief for Dia, Ruby was calming down from the rush of sex she had just indulged in, her member growing softer with each passing second. Figuring that it was in her best interest to try and take some sort of control of the situation, the twintailed girl nervously spoke, “Um.. Do you want me to come meet you now, or would you rather we meet up at home?”

An unsettling silence followed this. Dia was debating internally about whether she trusted her darling sister to return home safely, or whether the pair should meet up and return together. The part of her that was screaming to meet up with Ruby was fueled by a foreign feeling to Dia, the same wave of emotions that was plaguing her mind whilst the two of them walked together earlier in the day. Feeling like her heart was about to burst from her chest at any second, the black haired girl felt rushed to respond before her younger sister started to worry.

“Uh.. I-It’s fine, Ruby. You’re a big girl, you can get home safely by yourself. B-But if anything happens, you make sure to call me, do you understand?” Pushing aside her own selfishness, Dia felt a stinging pain of guilt piercing her chest as she finished her sentence. She didn’t know why, but she wanted to keep Ruby all to herself and spend all of her free time with the girl. Granted, she knew that she was an overprotective older sister, but she felt that she balanced it fairly nicely. The longer she thought of Ruby, the hotter her body became.

“O-Okay, I’ll um.. I’ll see you at home, onee-chan.” Surprised that Dia wasn’t insisting on meeting up and heading home together, Ruby hung up and let out a sigh of relief. As if a weight had been lifted off of her shoulders, she placed her phone back down and let her attention draw towards the unconscious Mari on the couch, her stomach still inflated from their deeds from earlier. Thinking that she had time for another round or two, Ruby could feel her groins start to stir as she felt the craziness from earlier start to cloud her mind once again.

Grabbing hold of Mari’s legs once again, Ruby felt like she was possessed by a demon that was compelling her to commit such adulterous deeds. Those feelings were pushed to the back and overtaken by the animalistic need to mate, and with that Ruby thrusted her hips forwards into the blonde girl’s stretched out pussy. The sloppy sound of wet skin slapping against skin filled the room with each forward movement of Ruby’s hips, the twintailed girl determined to let out all of the frustration that had risen from her sister’s phone call.

* * *

As the sun began to set, Ruby exhaustedly made her way back to her household, the pungent smell of sex emitting from her body as she had indulged in pleasuring herself with Mari’s body. After so many hours of committing adultery, the young girl still felt dissatisfied despite unloading the contents of her balls inside the blonde girl countless times. Hoping that no one would be around to welcome her so she could wash away the fatigue and smell, Ruby opened the front door cautiously in hopes of not alerting anyone to her presence.

Kicking her shoes off and placing them neatly to the side, she noticed the absent spot where Dia usually placed her own pair. Letting out a sigh of relief that she wasn’t going to be berated for staying out so late and not informing her older sister, Ruby made her way to the bathroom with a hop in her step. Closing the door behind her and running the bath, the twintailed girl dropped her clothes to the ground before marvelling at her reflection in the mirror. She still couldn’t believe that this  _ thing  _ had sprouted and grown overnight. A part of her was annoyed with having grown such a large, protruding member, but she was also thankful for the pleasure that this sinful dick had brought to her.

Untying her hair, Ruby sank into the hot bath and soaked in the soothing water, feeling her worries wash away as she calmed down. Leaning back, she started to think of the chain of events that had occurred that could possibly answer as to why things had grown crazy all of a sudden.

Everything was perfectly normal before going to Mari’s for the dinner party, but it wasn’t until they dished up the blonde girl’s cooking that things started to become weird. Of course, Mari owned up that she used some ingredients that anyone in their right mind should not have used, so that is a potential answer as to why the sudden growth spurts had occurred throughout the girls. They all returned home and slept, and that’s when the growth spurts became prominent, evident by her own dick, and Dia and Mari’s bodies growing curvier and thicker.

She couldn’t piece together just why her mind became clouded when she was near Dia and Mari though. When she was in the proximity of either of them, Ruby felt her mind becoming flooded with the compelling desire to pounce of them and indulge in their bodies, the animalistic desire to mate taking control. Then there was the obscene amount of semen she released while she was with Mari; of course she had only pleasured herself earlier in the day and the volume of that load was incomparable to the numerous that she had let out while fucking the blonde girl’s brains out.

Not able to find the answers she was looking for, Ruby figured that she could browse the internet after dinner in hopes of finding any pieces to the puzzle she found herself in. Finishing up in the bath, she found herself curious as to just how well endowed she was. Making a mental note to measure her member later in the night, Ruby wrapped herself in a towel and made her way to her bedroom. As she was opening the door to her room, she noticed a figure up the hall peek out of their door before hastily disappearing, followed by a slam of a door. Knowing that the only person who owned a bedroom up in the direction the noise came from was her sister, Ruby felt somewhat worried that her sister was mad at her for not informing her that she’d be arriving home so late, forgetting that Dia wasn’t home when she had arrived. Shaking those thoughts, she entered her room and changed in preparation for dinner.

* * *

Later that night when she was certain that her family was fast asleep, Ruby started to browse the internet in hopes of finding any answers to the questions that seemed to sprout one after another. Figuring that it’d be best to start off with looking up girls that suddenly grew a dick, she started searching forums for anything relating to it. Of course she was flooded with tons of doujinshis about it, but Ruby was just surfing through it all until she found a thread that caught her attention. “I suddenly grew a d*ck after eating my friends cooking,” reading the title out loud to herself, Ruby started to skim through it.

Minutes passed before she finally let out a sigh, leaning back in her chair and stretching. She thought she had hit the goldmine with this, but it turned out to be all for naught. The only thing she gained from the thread was that growing a penis seemed to be a popular topic amongst teenage girls and young adults. Deciding to try searching for another term, Ruby sat up and started looking for any information about sudden growth spurts. After minutes of scrolling, she started to bang her head against her desk as nothing of relevance was coming up.

“Ugh what did I expect, this is just like something out of fiction,” exhausted, Ruby was about to give up when the lightbulb in her head lit up. Tapping away at the keyboard, her eyes lit up when she found a thread that seemed to match exactly what she was looking for. Skimming once again through walls of text, Ruby was happy to find that there was at least someone else who found themselves surrounded by girls who underwent a sudden growth spurt.

Of course, she couldn’t take it at face value since it was the internet, but she felt like this was the hope she was looking for. After finishing reading the text, Ruby felt like she had just read what had happened to her in the past 24 hours. The author of this thread had apparently been struck with sudden nausea while out with friends, all the while their friends were oblivious to it. Then the following morning, all of their bodies had suddenly grown more sexy.  _ Yeah, this feels like déjà vu.  _ Then there was the part where they’d feel horny when near one another, followed by the adulterous acts.

This still didn’t answer Ruby’s questions, but she felt relieved that she wasn’t the only person crazy for experiencing such a thing. Curious as to whether the author had posted anything else relating to the matter, she searched for more threads from the same person. Then she struck the goldmine; the mysterious person online made a thread going into further detail about this phenomenon. Finding her eyes glued to the screen as she read word after word carefully, Ruby was oblivious to the time ticking away. When the young girl had finished reading everything, she looked at the clock and felt a cold sweat drip down her forehead; it was 11:25PM on a Sunday night and she had school the next day. 

Wanting to head to bed, Ruby’s mental note from earlier in the evening suddenly came to mind; she was supposed to measure her member and see just how large it was. Scrambling around to find a measuring tape, she only managed to find a foot long tape. Thinking that it’d be enough, Ruby reached down and grabbed hold of her flaccid dick and ran the tape along the length of it. Feeling somewhat proud with herself, the young girl measured at 11 inches soft. She wanted to check just how large it was while erect, but she didn’t want to go out and search for a longer tape in the middle of the night while her family was asleep.

Feeling like she was alone and the only person awake at such an hour, Ruby was spooked and had to hold in a scream when a knocking came from the other side of her door. No one should be awake at this time of night, and if it were her parents checking up on her, she knew she should be asleep as well. Hurrying to get under the covers and pretend she was asleep, Ruby couldn’t help but be on edge as the door creaked open before creaking closed. Thinking that whoever it was that came to check up on her had left, the young girl was unaware of a figure approaching her bed.

A sensual voice filled the room as Ruby almost jumped on the spot from the sudden intruder speaking aloud, “Ruby.” She knew that it was Dia’s voice, but there was something different about it. Not wanting to get caught being awake at such a time of night, she just laid there with her eyes closed, still pretending to be asleep as the footsteps drew closer before coming to a stop. “Forgive your older sister, Ruby.” Not sounding sincere, Dia started to undress at the edge of the bed, the sound of clothes falling to the ground alerting the younger girl.

She was about to speak up when she was caught off guard by the now naked Dia crawling under the covers and pressing her body up against Ruby’s. In the pitch black room, the pair of sisters were sharing a bed. To onlookers, this would’ve been a perfectly normal thing. But to Ruby, she was doing her best to hold back and pretend she was asleep in hopes of Dia either leaving or falling asleep herself. Much to her dismay, Dia showed no signs of wanting to sleep, her hands roaming Ruby’s body.

“You know Ruby, your sister’s about to commit a huge sin,” picking herself up and throwing the covers back, Dia started to undress Ruby, tossing the girl’s clothes to the floor without a care in the world. Driven by madness, the black haired girl was intent on making her younger sister her prey. Ruby knew that there was something wrong with her sister, given that she was absent from dinner for the first time in what felt like ever, and that Dia was also refusing to leave her room the entire night. She knew that she had to put a stop to things before they committed such a taboo act, but Ruby could feel the madness start to creep up on her and plague her mind.

“My body yearns for you, Ruby. While we were together earlier today, I was doing my best to show some self control,” Dia spoke sensually, her tongue rolling everytime Ruby’s name left her lips. As her hands roamed to Ruby’s pelvic region, she was caught off guard by the protruding member but thought nothing of it as she started to pump her hand up and down on the flaccid dick. “Ruby, you’re such a good girl. So cute, so precious. I’m going to make you mine, okay?”

Ruby felt like she could quit this act, to speak up and try and bring Dia to her senses, but a part of her wanted to let things continue. She wanted her sister to take the dive and kick things off between the pair before she started to take control of things herself. As Dia’s hand kept its rhythm of pumping her dick, Ruby could feel the blood start to flow down to the member as it began to grow erect. Dia let out a giggle as it grew too large for one hand to handle before using both of her hands to give attention to the throbbing manhood.

“Ruby, do me a favour and make me a mother,” demandingly, Dia abruptly stopped what she was doing and lifted her body upwards until she was resting on Ruby’s lap. Ruby herself could feel just how excited Dia was by how damp her lap was becoming, feeling a tingle run up her spine at the thought of giving her sister the same treatment she gave Mari. Almost as if she was in a rush, Dia lifted herself up and aligned the engorged cock head with her drenched womanhood. With heavy breaths, the older girl spoke, “And HERE. WE. GO.”

As the final word left her lips, Dia took the drop as she plunged her hips downwards with reckless abandonment, a scream erupting from her as she felt like she was being torn in half. Ruby’s dick was pressed up against her sister’s cervix, trying its best to force its way into the girl’s most forbidden place. Gasping heavily, Dia struggled to speak, “J-Just stay asleep, Ruby. I don’t want you to see how depraved and ugly I am right now.” With this, she started to raise and drop her hips along the length of Ruby’s shaft, her large breasts bouncing up and down with a loud slap.

Ruby couldn’t hold back any longer as she grabbed hold of Dia’s hips before letting out sensually, “O-Onee-chan!” The young girl started to pull her sister’s body downwards with each bounce, intent on burying her monster to the brim inside of Dia. She didn’t care about holding back and letting the black haired girl do as she pleased and indulge in her own guilty pleasure, Ruby just wanted to jump into the river of madness and desires. Letting out a gasp, Dia didn’t have time to process that her beloved sister was awake as her pleasure senses were sent into overdrive by the added force being applied with each downward plunge.

Sitting there atop of Ruby’s cock, Dia let out a smirk as she continued rolling her hips and indulging herself in the pleasure, intent of taking control of the situation. A part of her craved this, to have Ruby completely helpless as she was toyed with. She had come here with the intention of taking advantage of the slumbering Ruby, indulging herself and taking care of her sexual needs by doing as she pleased without an ounce of resistance. As she continued to work her hips, Dia felt thrilled by finally crossing that forbidden line that has been plaguing her throughout the day.

Stubbornly pushing herself faster and rougher, Dia was struggling to hold back her moans as to not make too much noise as she heaved and squirmed through the sinful pleasure. She was addicted to the pleasure and cause of this bliss as she continued to buck her hips faster, fucking herself senseless on her own sister’s cock and savouring the pleasure all the while. Dia’s mind should’ve been full of feelings of guilt, but instead it was plagued with an intense need for release, the excitement of mating with her own sister driving her onwards.

Ruby was savouring the forbidden joy of committing such a taboo act with Dia of all people, as she laid there and she let her sister bounce faster and deeper with each continued buck of the hips, not an ounce of restraint being shared between the two as neither of them could get enough of this feeling. The shameless act they were both committing only fueled them as Ruby’s grip on Dia’s hips hardened before, on Dia’s next downwards thrust, the younger girl mustered all her strength in forcing the older girl down, intent on burying her monstrous dong inside Dia’s pussy.

With a popping noise followed by a loud shriek of pain from Dia, Ruby knew that she had just forced her way through Dia’s cervix and into the girl’s womb. As if it were a perfect fit, Ruby let out a moan of relief herself, knowing that she wasn’t going to last much longer in this madness. As Dia’s mind struggled to keep track of what had just happened, she knew that she had to indulge more in the aching feeling building up inside of her. The sound of their bodies slapping together filled the room as Dia resumed bucking her hips, the girl growing dizzier with each passing second.

The black haired girl wasn’t sure just how sex, the thing she shunned and thought of as nothing more than a means of entertaining oneself for 5 minutes, could be so intense. With such a large member stretching her wide open, Dia was incapable of making rational thoughts as she felt a heat wash over her body. Riding Ruby’s dick and trying to maintain the pace was wearing her down mentally, she knew it was hopeless to try and keep up with her sister. With each motion up and down, she didn’t know what to expect any longer; she just wanted to drown in pleasure and worry of the consequences later.

“Onee-chan, you’re my cock sleeve now, do you understand?” Ruby groaned, the switch inside of her being flipped as the vulgar tongue she showed Mari earlier in the day was now rising to the surface as she throbbed with each movement. She was growing desperate for release, bucking her hips upwards as the building orgasm was rising to the surface, her body aching for release. Within a moment, Ruby couldn’t take it any longer as she let out a loud howl to signal the start of her orgasm.

An eruption of hot, gooey cum flooded Dia’s unprepared womb as she let out shrieks as she struggled before giving in to the madness as she let her own orgasm take its toll. Overwhelmed by the sudden foreign feeling, Dia felt as though she was falling deeper into the sea of lust as the sensation of being pumped full of cum had thrown her off the deep end. As shot after shot of potent baby batter continued to erupt inside her womb, Dia felt intoxicated as she was hit with a rush of emotions. She knew this was wrong, but this felt like the most natural thing to her.

Ruby didn’t stop cumming as she held Dia’s body there atop of her, the dickgirl’s body twitching with each passing second as the sheer volume of her load was enough to deform her sister’s body, making it look like she was pregnant. With an inflated stomach, Dia was struggling to process that this was reality. She had read and looked up sex occassionally online to pique her curiousity, but she never found anything like this before.

Straining under the weight of Dia, Ruby knew that this wasn’t enough to satisfy herself. Realising that Dia was still conscious, albeit she was letting out inaudible noises, the young girl knew that it was going to be a long night for the pair. Exasperated and gasping for breath, Ruby took a second before demanding, “O-Onee-chan, I need more.” Both girls could feel their bodies burning up, neither of them wanting to take a second to cool off. They knew this whole situation was wrong, but now that they were so deep into it, it’d be a missed opportunity for the two to indulge in their own guilty desires.

“A-As if you needed to tell me,” Dia struggled to form words, her mind turned to nothing more than mush from the intensity she had just been through. The thought of indulging in more of that madness sent a shiver down her spine as she licked her lips, knowing fully well that things between the two of them were never going to return to what it was. Throwing all reasoning out of the window, Dia started to buck her hips once again, the feeling of Ruby’s cock reshaping her pussy wearing her down.

“I-I hope you’re ready, Ruby, because I’m not stopping until the sun rises!” With that, the two continued their adultery.

* * *

As the sunlight poured through the curtains of Ruby’s room, the Kurosawa sisters were both sound asleep, although the pair were still in the same position they were in at the start of their sex-filled night. Dia was upright on Ruby’s lap, her stomach protruding from her body alarmingly, her womb being flooded with such an insane volume of cum that, with Ruby’s massive dick plugging her pussy up, left it nowhere else to go, resulting in Dia’s womb being stretched beyond breaking point as her inflated stomach hid Ruby’s small figure beneath it.

It wasn’t until Ruby’s alarm went off that the pair of them were brought back to the realm of the living, the two having barely gotten any sleep. Taking a moment to take in her surroundings, Ruby was shocked to realise that Dia was still resting on her lap, her own dick plugging up her sister’s pussy. “O-Onee-chan?” Worried that their parents would walk in on them if they dallied any longer, Ruby wanted to try and put an end to the madness here, for now at least.

Then she noticed Dia’s appearance. The girl’s long black hair was no more, instead it was jaw-length.  _ So she got a haircut yesterday while out shopping.  _ Somewhat surprised that Dia had cut her hair, Ruby’s eyes trailed downwards to her naked body. Her breasts seemed even larger than yesterday, although she couldn’t quite tell if that was because of them resting on Dia’s inflated stomach or not. Struggling and twisting her body, Ruby tried to free herself from the heavy body atop of her.

Then she remembered what she had learned while browsing the web last night. She wanted to explain to Dia exactly what was happening to them, that their actions were being influenced by something they couldn’t control. Ruby was about to speak up when Dia beat her to the punch, “R-Ruby.. Fuck I’m sore.” Exhausted, Dia’s body fell to the side as she dropped off of the bed and onto the floor, her pussy no longer plugged up by Ruby’s dick as a flood of cum started to pour out the stretched out orifice, forming a pool beneath the black haired beauty. Knowing that they were supposed to leave for school soon, Ruby couldn’t help but worry about the growing mess starting to form on her bedroom floor.

  
Frustrated and confused with what she should do, Ruby let out a groan.  _ How am I supposed to explain this one? _

**Notes for the Chapter:**

> So yeah, got around to this one. What a mess.

**Author's Note:**

> So this one came to me randomly one morning.  
> Decided to just write it.


End file.
